1. Field of the Invention
This invention relates to computer circuitry and, more particularly, to apparatus for storing information of different formats in and deriving that information from a frame buffer.
2. History of the Prior Art
Information to be presented on a bitmapped computer output display may appear in many different formats. For example, each pixel on the display may appear in black and white, in color, or as a shade of gray. In order to represent black and white, only a single bit of digital information is required. Color is typically represented by either eight or twenty-four bits of digital information at each pixel. If it is desired to present approximately one-half million twenty-four bit color pixels on an output display as occurs with screens displaying approximately 800 by 600 pixels, then it is necessary that a frame buffer have storage for one and one-half megabytes of digital information (three bytes per pixel). Such a frame buffer would also be capable of storing over a million pixels of eight bit color information if the information is directed to the proper storage positions. However, a typical frame buffer does not have circuitry for directing the digital information to storage which correctly represents the two different formats of information.